Diodes are one of the most commonly used electronic devices. The types of traditional diodes are schottky diodes and PN junction diodes. PN junction diodes can withstand high reverse blocking voltage and has better stability. However, PN junction diodes have a larger forward voltage and a longer reverse recovery time. Schottky diodes are based on the principle of metal-semiconductor junction. Schottky diodes have a lower forward voltage and a faster reverse recovery since it has no minority carrier accumulation during the forward conduction. However, schottky diodes have a larger reverse leakage current and a poor temperature characteristic. There is a tradeoff between schottky diode's breakdown voltage and the forward voltage, which is called the “silicon limit”. In order to improve the breakdown voltage of a schottky diode, the thickness of drift region must be enhanced and the doping concentration of drift region must be reduced, which leads to an increase of forward conduction loss. Therefore, the main application field of schottky diode is for low or middle voltage applications.
In order to improve the schottky diode's breakdown voltage without increasing its forward voltage, the super-junction structure is introduced into the schottky diode's drift region. For example, Chinese patent application “A super-junction schottky semiconductor device and its preparation method” (application number: 201210141949.4) provided a schottky diode based on the charge balance principle. However, the schottky junctions existing in schottky diodes are located on the surface of the devices, so that the current capacity of the schottky diode is limited since the surface area is limited.